A grapple bucket apparatus which is disclosed in Japanese Patent Application Laid-Open No. H11-36355 is composed of, a bucket connected to at a front end portion of an arm of a construction machine which is vertically swung, to be pivotable vertically, and a grapple device including two grapple members spaced substantially at the same interval as an opening width of the bucket and pivotally supported on a base end portion of an open mouth portion of the bucket to be pivotable in a direction to close the open mouth portion of the bucket.
A configuration of the conventional grapple bucket apparatus will be described with reference to FIGS. 1 to 3.
In FIG. 1, reference numeral 1 represents a vehicle body for a conventional power shovel, reference numeral 2 represents a boom provided therein to be able to be swung up and down, reference numeral 3 represents an arm connected to a front end of the boom 2, and reference numerals 4 and 5 represent cylinder devices for the boom and the arm to swing them up and down, respectively. In addition, reference numeral 6 in the drawing represents a grapple bucket apparatus mounted on a front end of the arm 3.
As illustrated in FIGS. 2 and 3, the grapple bucket apparatus 6 includes a bracket 7 connected to the front end of the arm 3 to be pivotable vertically, a bucket 8 supported on a front end of the bracket 7 to be rotatable on an axis in an extension direction of the arm 3, and a grapple device 9 mounted on a base end portion of an open mouth portion of the bucket 8 to be pivotable in a direction to face the open mouth portion of the bucket 8.
A cylinder device 10 for a bucket provided along the arm 3 is connected to an upper portion of the bracket 7 through a link mechanism 11. Further, the bucket 8 is rotated by a hydraulic motor 12 provided in the bracket 7 through a ring gear and a pinion (not illustrated). A plurality of digging teeth 8a is attached to a front end of the bucket 8. Further, there may be a bucket 8 not provided with the digging teeth 8a. 
The grapple device 9 includes, a rotational shaft 14 pivotally supported on a bracket 13 provided at the base end portion of the open mouth portion of the bucket 8 in parallel to an opening width direction of the bucket 8, and two grapple members 15a and 15b of which base portions are fastened to both end portions of the rotational shaft 14 and which are curved in a concave shape to face the open mouth portion of the bucket 8. In addition, front ends of both the grapple members 15a and 15b are connected with a connection plate 16 for reinforcement of them as one purpose so that a long material is easily grappled. The interval between both the grapple members 15a and 15b is substantially the same as the opening width of the bucket 8, but an interval between front end portions of both the members is narrower than an inside dimension of the bucket 8 and the front end portions thereof are inserted into the bucket 8 along an inner wall surface of the bucket 8 with a small clearance. Further, the connection plate 16 is positioned inside the digging teeth 8a (the front end edge of the bucket when there is not digging teeth 8a) and further, extends along a bottom wall surface of the bucket 8 with a small clearance. Outer end step portions where the thicknesses of both the grapple members 15a and 15b are changed are configured as stoppers 17 that contact opening edges of the bucket 8. A saw blade-shaped gripping blade 16a is formed at the connection plate 16. Further, the gripping blade 16a of the connection plate 16 may have a linear shape.
A bracket 18 is provided in a protruding condition on the rotational shaft 14, the one end portion of a grappling cylinder device 19 of which the other end portion is pivotally supported in the bracket 13 provided at the base end portion of the bucket 8 is connected to the bracket 18, and the grapple members 15a and 15b are pivoted with respect to the bucket 8 by an extension and contraction operation of the cylinder device 19.
In the grapple bucket apparatus 6 configured as above, the boom 2 and the arm 3 are swung up and down and the bucket 8 is pivoted by extending and contracting the boom, arm, and bucket cylinder devices 4, 5, and 10, and as a result, vertical and anteroposterior positions and attitudes of the grapple bucket apparatus 6 are changed and further, a horizontal attitude of the bucket 8 is changed by rotating the bucket 8 with respect to the bracket 7.
In grappling a lumber, in addition to the above mentioned operation, the grapple members 15a and 15b are pivoted with respect to the bucket 8 by extending and contracting the grappling cylinder device 19. As a result, as represented by a chain line of FIG. 3, a lumber 20 is grappled between the grapple members 15a and 15b and both side walls of the open mouth portion of the bucket 8. In this case, by picking up the lumber 20 or changing a direction thereof with the connection plate 16 and the front end portion of the bucket 8, an attitude of the lumber 20 is trimmed so as to be easily grappled.
In excavating the ground surface, the grapple members 15a and 15b are pivoted to the bucket 8 side by extending the grappling cylinder device 19. As a result, as represented by a solid line of FIG. 3, front end portions of the grapple members 15a and 15b are inserted into the bucket 8 along both inner surfaces of the bucket 8 and further, the connection plate 16 is also located along the bottom wall surface of the bucket 8 inside the digging teeth 8a of the bucket 8.
In this state, the front end portions of the grapple members 15a and 15b and the connection plate 16 do not interrupt the excavation operation of the bucket 8 and as a result, the excavation operation by the bucket 8 is performed by extending and contracting cylinder device 4, 5, or 10 each.
The conventional grapple bucket apparatus mentioned above can perform both excavation of the ground surface and grappling of the lumber, and particularly, an operational effect in which the lumber can be piled up at a predetermined place may be expected by driving the construction machine while the lumber is grappled.
However, when the grappled lumber is long, the grappled lumber may contact the other thing, for example, a clump of trees near a forest road while the grappled lumber is transported, so that it becomes impossible to transport the lumber.
In this case, a worker needs to cut a lumber having a length longer than predetermined length into lumbers each having a predetermined length by using a cutting device such as a chain-saw and the like.
Further, the worker heretofore cuts each of lumbers after logging into a predetermined length, and the cutting work itself is a heavy labor and a burden to the worker.
Moreover, standing trees cannot be logged by using the conventional grapple bucket apparatus.
In view of the aforementioned, it is an object of the present invention to provide a grapple bucket apparatus that can cut materials such as a lumber grappled by using a grapple device in the state that the materials are grappled, so that the apparatus can simply cut and log the grappled materials after logging or standing trees before logging to reduce a burden of the worker and can, in advance, cut long materials grappled by using a grapple device before transporting the grappled materials to allow the grappled materials to be transported without a trouble in which the grappled materials contact the other things.